The invention relates to a damping strut, and more particularly to a damping strut having a frictional wedge member cooperatively connected with a load spring to damp a movement.
Shock absorbers and struts and more particularly frictional damping struts are used to absorb and damp oscillatory movements in a number of applications. Applications include vehicles and machinery that are subject to repetitive oscillatory movements and vibration. Generally, a load is absorbed by a spring means while oscillations are absorbed and damped by viscous or frictional movement of cooperating parts.
Frictional damping strut assbemblies may be incorporated into a tensioner assembly. A tensioner may be used to preload an engine drive belt in order to maximize operational efficiency and to minimize noise and vibration during belt operation.
Representative of the art is EP 812999B1 (2002) to Bodensteiner which discloses a dual spring tensioning-unit having a damping element with a convex wedge shaped surface that can be contacted with a similar surface on a plunger.
Reference is also made to pending U.S. application Ser. No. 09/954,993 filed Sep. 17, 2001 which discloses a damping strut.
What is needed is a damping strut having a spring cooperatively connected to a radially expandable frictional damping member to provide proportional frictional damping. The present invention meets this need.
The primary aspect of the invention is to provide a damping strut having a spring cooperatively connected to a radially expandable frictional damping member to provide proportional frictional damping.
Other aspects of the invention will be pointed out or made obvious by the following description of the invention and the accompanying drawings.
The invention comprises a frictional damping strut. An inner damping member is axially engaged with an outer housing. The outer housing is connectable to a tensioner arm. A wedge member connected to an immoveable mounting member is axially engaged with an inner portion of the inner damping member. The outer housing is axially moveable relative to the wedge member. A spring bears upon and urges the outer housing away from an end cap. The end cap comprises a rod, which extends axially within the wedge member and has an end connected to the inner damping member. The rod transmits a spring load force from the end cap to the inner damping member such that the inner damping member radially expands against the outer housing in response to the spring load force, thereby creating a frictional force between the inner damping member and the outer housing which damps an outer housing movement in proportion to the spring force.